As is well known in the art, such a method is to be used for instance in telecommunication networks wherein a network timing reference signal is to be transported over the network but wherein data are transported over a network segment synchronized to a timing reference signal internal for this network segment. The network timing reference signal has to be transmitted over this network segment although it may not be used therein. Within a segment of an ATM (Asynchronous Transfer Mode) network, data may for instance be transmitted over a telephone line in accordance with the ADSL (Asymmetric Digital Subscriber Line) specifications. The transmission of data packed in ADSL frames over the telephone line between a transmitting and a receiving modem is synchronized to the modem clocks. Nevertheless, network layer specifications require that the ATM network timing reference signal be transparently transported over this ADSL network segment. From the point of view of the network segment, the ATM network timing reference signal thus is an incoming clock signal which unaffectedly has to appear at the exit of the ADSL network segment, i.e. at the output of the receiving modem. This could be done by sending the network timing reference signal over a separate transmission means or over the telephone line thereby using part of the transmission capacity of this line. Moreover, this way of transmitting the network timing reference signal implies a considerable complexity increase for the transmitter and receiver.